Uncommon exoplanet 30 EP

Kepler-398 b

RA 291.4689° · Dec 40.3437° · exoplanet

Loading sky survey…

🌌 View in 3D star map

Tonight’s visibility

Computing the sky for your location…

Score breakdown

· 4 badges

30 pts · Uncommon

Uncommon 33 pts → Rare

Earth-sized +16
Multi-planet system +6
Confirmed exoplanet +5
Found by Kepler +3

Total score 30

3 more points to reach Rare.

Badges

Confirmed exoplanet · +5
Earth-sized · +16
Multi-planet system · +6
Found by Kepler · +3

Trivia

Could we get there?

Verdict. Hopelessly far for any craft humanity can build today.

Getting there

Aboard Voyager 1. ≈ 10.2 million years at Voyager 1's speed (17 km/s).
Fastest probe ever. ≈ 903.2 thousand years even at the Parker Solar Probe's 192 km/s.
At 10% light speed. ≈ 5785 years in a starship at a tenth of light speed.
Distance. 578 light-years from Earth.

Look-back time

Look-back time. The light you'd see left around the year 1448.

Saying hello

Say hello. A radio message and its reply would take 1157 years round-trip.

Standing on it

A year here. A full year lasts just 4.1 Earth days.

By the numbers

Size. Around 93% of Earth's width.
Mass. About 0.7× the mass of Earth.
Your weight. You'd weigh about 0.9× your Earth weight standing here.
Temperature. Around 482°C — hotter than a self-cleaning oven.

How we found it

Discovery. Found by Kepler using the transit method.

Cosmic context

Crowded system. One of at least 3 planets orbiting its star.

Properties

density gcc: 5.12
discovery facility: Kepler
discovery method: Transit
dist ly: 578.454
eccentricity: 0
eq temp k: 755
insolation: 81.287
mass earth: 0.749
name: Kepler-398 b
orbital period days: 4.0814
radius earth: 0.93
sys num planets: 3

About Kepler-398 b

Kepler-398 b is an uncommon exoplanet. It lies about 578.5 light-years from Earth, has an equilibrium temperature near 755 K, spans roughly 0.93 Earth radii and weighs about 0.75 Earth masses.

One of at least 3 planets orbiting its star.

How to see it

Like any astronomical target, Kepler-398 b is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. The visibility panel above works out tonight's viewing window for your saved location.

Why Kepler-398 b is an uncommon exoplanet

Kepler-398 b scores 30 points on Spacedle's rarity scale, which places it in the uncommon tier. Another 3 points would lift it into a rarer tier.

That score comes from 4 science badges — Confirmed exoplanet, Earth-sized, Multi-planet system and Found by Kepler — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.